And now the tennis star, 37, sent what some have interpreted to be a thinly veined message of support to the royal mum-to-be during her Oscars speech.
Serena presented the film A Star Is Born at the 2019 Academy Awards on Sunday in Los Angeles, which stars Bradley Cooper and Lady Gaga, and spoke about pursuing about your dreams.
She said: “When we are young, we all have dreams of what we can accomplish in life.
“Having the dream is easy. Making it come true is hard. Whether that dream is becoming an actor, a tennis player or a singer, like Ali in A Star Is Born.
“In tonight’s nominee for Best Picture, we see through Ali’s eyes the highs and the lows on the journey to stardom.
“There’s the rush of fame, the pressure of success – and the heartache that comes with sacrificing love for career… or career for love.”
Meghan, 37, famously gave up her acting career on Suits and moved to the UK when she and Prince Harry announced their engagement in 2017.
She also shut down her social media accounts and closed her lifestyle website The Tig.
Serena and Meghan are believed to have struck up a friendship at the Super Bowl in 2010.
The duchess has supported her friend at Wimbledon over the years, cheering her on at the Ladies’ Single Final with sister-in-law Kate last July.
Serena and her Reddit co-founder husband Alexis Ohania attended Meghan and Harry’s wedding on May 19 in Windsor.
The Duchess of Sussex is due to give birth to her first child this spring. Following her trip to New York last week, she and Harry flew to Morocco for a three-day visit on Saturday, in what will be her last overseas engagement before the baby arrives.
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